Lida forms the basis of the search ranking algorithm used by UK Prostate Link.
Users of this website can browse or search for information on a given topic across 50 major websites. Search results are ranked according to Lida score.
A sample search for “radiotherapy”. UK Prostate Link uses the Lida score to rank the order in which web pages appear in search results.
Constitution of UK Prostate Link
UK Prostate Link was commissioned by the Prostate Cancer Charter for Action in 2005 to help improve the accessibility of good quality information about prostate cancer on the internet for patients, their friend and family members, carers and professionals.
The PCCA was wound up in 2010, but UK Prostate Link has continued with no-strings funding from Takeda UK. The website is managed by a steering group comprising:
- Emma Malcolm, CEO of Prostate Action (Chair)
- Tim Elliot, Male Cancers Lead, Department of Health
- Liz Woolf, Head of CancerHelp, Cancer Research UK
- Debbie Clayton, Information Manager, Prostate Cancer UK
- Chris Alcock, Consultant Oncologist, Oxford Radcliffe NHS Trust
- Ben Challacombe, Consultant urologist, Guy’s and St Thomas’s Hospital,
Minervation provides the website hosting, design, content and holds the budget for this project.
How it works
We were tasked by the PCCA to come up with a way of ranking search output by quality. This meant that:
- It had to include usability and accessibility as well as reliability. Our users told us this.
- It had to be done by humans, because computers cannot reliably evaluate issues of accessibility, usability or reliability. Measures based on popularity or user voting are too biased to be usable.
- It needed to allow the full range of information “quality” to be represented, from the most rigorous systematic review right down to an individual opinion or blog post.
- Given the scale of the enterprise (around 1,200 pages were assessed for the initial launch of the site), the instrument needed to be practical.
- It needed to be valid and transparent so that we can justify giving one piece of information a higher score than another.
For this reason, UK Prostate Link uses we abbreviated the instrument and adjusted the weighting to give greater emphasis to Reliability (which has fewer items than Usability).
Usability Questions
- Is the site accessible without a login?
- Does the site conform to web Accessibility standards?
- Is the site design clear and transparent?
- Is the site design consistent from one page to another?
- Can users find what they need on the site?
- Is the format of information clear and appropriate for the audience?
Reliability Questions
- Is it clear who has developed the web site and what their objectives are?
- Does the site report a robust quality control procedure?
- Is the page content checked by an expert?
- Is the page updated regularly?
- Does the page cite relevant sources where appropriate?
As with the main Lida instrument, each item is scored on a four point scale: 0, 1, 2 or 3. This form of Lida has been validated. Watch out for future Lida blogs where we will present the details of how we validated it.
Each page gets its own “report card”, showing the score it has receive for each item. In cases where the page has scored less than the maximum of 3 points for an item, the reviewers add qualitative remarks to explain why.
A typical UKPL score sheet for a single web page.
The instrument has been used to evaluate the quality of around 2,000 web pages dealing with different aspects of prostate cancer. Around 100 new pages of content are added or reviewed each month, providing an up-to-date signposting system.
Browsing or searching
Many people prefer browsing to searching, especially those who understand how poor website search engines can be. Clearly, users of a web site need to be able to do both.
The most common user requirements are used as a starting point to help users to browse to the right information for their needs.
By working with the end-users of UK Prostate Link, we were able to identify the topics that matter most to them and to present information from different sources appropriately. Here, Lida functions as a way to rank the content within categories. In this way, Lida optimises both searching and browsing, as long as information is accurately classified.
Users of UK Prostate Link can further customise their searches by filtering according to whether the information is intended for patients or for professionals. They can also select UK information separate from International information.